Control apparatus of the above outlined type are known. For an example of such a control apparatus the pressure control device is typically adjusted to a certain value which corresponds to the maximum admissable user pressure. If, for instance, a user like a tilt cylinder or a lift cylinder of a loader is moved until its abutment position is reached and if the cylinder is held in this position, then the pump destrokes and thus reduces its volume flow so far that the maximum set or adjusted value of the pressure at the pressure controller is maintained. This is done independently whether there is a need or no need to have such a high pressure available for the user in this state of operation.